Imaging of moving scatterers in a synthetic aperture radar (SAR) image is a challenging problem as targets will both smear and be displaced in azimuth. One technique which overcomes this limitation is the velocity SAR (VSAR) algorithm which was originally proposed by Friedlander and Porat in 1997. This technique provides the full Doppler spectrum at each and every pixel of a SAR image, which then allows for correction of the distortion caused by the radial motion. This chapter describes the signal processing of the VSAR algorithm and presents the first experimental results using both land and airborne multi-channel radar systems developed by the US Naval Research Laboratory (NRL). These examples demonstrate the VSAR correction for a variety of moving backscatter sources, including automobiles, ships, shoaling ocean waves and tidal currents. Two further applications of VSAR are also briefly covered in the chapter. These being the application to target detection and velocity inverse SAR.